XS650 Bobber build


XS650 Addict
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Buffalo, NY
Hello folks, I've been kind of a lurker here for a while and have silently been working on this 1979 xs650 I bought a while back for $500. It was half disassembled but the previous owner was a good neighbor of a close friend of mine and by friend told me the bike was only apart about a year and was regularly ridden prior to that, so I scooped it up.

here she is after I re-assembled her to see how she ran/rode


I bought a universal hard-tail kit on ebay that was basically a couple pre-bent tubes and some axle plates (I later regret this due to the modifications required for the XS, should have done a TCbros)

started tearing the bike back down to a roller besides the motor being in there

used the motorcycle jack to play with ride height with the triple trees loose and no rear shocks until I figured out roughly where I wanted the rear axle to sit.


Then I eyeballed the right side tube and tacked the plate up, and I liked the look of it so I made a matching left side.....

Then I picked where I wanted to cut and went at the beast with a grinder and sawzall


Then I bolted the wheel into the axle plates and sleeved the tubes so they would sit in the right spot with the remaining part of the stock frame's lower tubes, and then set the top tubes in place to mock it up


Decided it's perfect enough so I marked the location of the top tubes and welded the two sides of the hardtail all up and then called it a night.




Next I sleeved and pinned the tubes running from the axle plates into the stock frame's downtube and put a couple tack welds on them to put them in place, sleeved (haven't pinned yet but will) the lower tubes to the stock frame and put two stitch welds there, then mocked up front fender on the rear (it's too narrow though) to set a brace/crosstube that will triple as lateral support, a mount for the fender, and a mount for springs to a solo seat ( I tacked this tube in place as well).




Now, before I throw up the next pic I'll explain.....

at this point I'm heavily conssidering re-using the stock tank for this project for a few reasons.

I've spent some time over the last several days looking at XS bobbers using sporster peanut tanks and noticed a few things I really hate that are basically apparent across ANY XS bobber....
-The tank's bottom doesn't sit level
-The deepest tunnel version (closest to level they can get) is a stock 2.1gal tank, which is fucking useless. i'd rather not refuel every 80 miles.
-there is ony one petcock, and its dead in the middle on the right side. This is a problem because the tank is not level, so not only is in in a really shitty place thanks to the top engine mounts and the head placement, but this also means you'll "run out" of fuel sooner with gas left in the bottom you'll never get to use. (shrinks the mileage per tank even more on the 2.1gal version)

So basically, that means if I want the sportster shape tank, I have to buy an unfinished shell of one and make my own tunnel to attempt to get it level, then weld the tunnel in and weld bungs in for petcocks. This would easily run me something in the $300 neck of the woods. F**K THAT.

A replica 3.1 gal sportster tank is about $150-175 after purchase, shipping, gas cap, and petcock(which still needs to be split for two carbs and hope it flows enough for both)

This tank is free, sits level, and has the petcocks where I need them. only issues are that the petcocks leak ($40 a piece) and the rear mount on it now will sit where my nutsack should be so I'll have to address that somehow (not worried about this)

I could probably come up with a cheaper solution to replacing with OEM petcocks and be able to use this tank for about $50 or less.


the only other tank I like is the "wassell", but that's also only 2gal again....I can't find an "oversized" wassell.....


as you can see this tank actually sits level, and it happens to have dual petcocks at the rear of the tank so it would be the perfect setup.....if I could find one around 3 gal I'd be IN.

ordered some pieces to keep moving forward.

Bar-End turn signals....hopefully these are viewable enough from behind while I'm on the bike so that I don't have to run rear signals


Solo seat with springs:


Might re-upholster the seat in a brown or tan leather instead though...

cut the remainder of the original subframe off


tank back on for mockup


My buddy Checko called me up and convinced me that I should let him lend a hand...

made up plates to tie in the lower crossbar that "tee's" off the bottom of the backbone tube



then chopped the part of the rear tank mounting tab, and made a new mount that uses a rubber isolater and a wing nut


ordered another $100 worth of parts lol

-6" wide plain-jane basic fender for rear wheel (been using a spare front fender for the mockup but it's way too narrow and widening it would be a PITA)

-(2) 45* silicone couplers, and (2) Cone mini-filters to attach to the carbs while still being able to clear the new frame tubes

-set of drag bars

So far, this thing has been really fun to build.....the cost-fun ratio I'm getting on this build far exceeds that of my Honda CB550 cafe build (mostly because of how much money I've spent collectively on that one)

$500 for the bike, $115 for the universal hardtail kit, $35 for the sidemount tail light, $20 for the bar-end signals, $60 for the seat with springs and pivot mount, $50 for the fender, $30 for the bars, $20 for filters and couplers...... Thanks to re-using the stock tank I'll be under $1000 in parts/investment into this build unless I decide to buy whitewall tires (which I consider a maintenance item anyways and will most likely do next season anyhow)

Customizing bikes is SOOOOO much nicer than customizing cars. (my other hobby)

Got lots done today.....

broke the bike down to a bare frame to finish up all the welding





Made a brake-stay for the rear caliper, and welded on the axle adjuster plates



(wow, these pics didn't look nearly at terrible in quality on my phone......I appologize)

fender and drag bars came in, so checko and our other buddy slaw decided to come by and lend a hand.

I kinda forgot to take pictures when I started working on it, so these are after I already trimmed the fender short and decided how I was going to mount it.....






I mocked up some riser extensions to get the bars to clear the forks now that they're pushed through the top trees

decided on some colors and such.....mostly influenced by the springs that came with the solo seat (they are antique copper in color, powdercoated)....

so I started out by picking up some copper bicycle pedals so I can modify one for the kickstarter


I'm going to sleeve the hardline for the rear brake in copper tubing from the forward control to the rear caliper, as well as the shift linkage rod the same way

Then for the paint scheme, I'd like to do an inlay on the sides of the tank and the middle of the rear fender pearl white, with the rest a dark metallic blue, and use a copper color as accent striping.

no idea what specific shade of blue, need to get my hands on a chip book to peruse.

my buddy Luke came by and helped me throw the motor back in the frame so I could do a quick mockup and see what else I still need to fab up.....

Before diving into that, I had this idea to maybe use a vintage lunchbox as the case for my battery and electronics....so I snagged one on ebay for $12 shipped.


it is a bit smaller than I had envisioned....stock battery won't work.


So then I made a cardboard template to see if I can fit the electronics in there.....




It looks like I should be able to fit the same mini battery I used on the CB550 in the space that's left....the only thing not in the box is the starter solenoid which I have to try a battery in here first to see if there's room to put that in as well.

So now we've got the motor back in, seat on, tank on, rear fender on, and I started mocking up new stuff...

I knew ahead of time that it was going to be tight clearances with the new frame and the carbs, so I picked up some 45* silicone couplers to follow the frame to be able to run filters......


I haven't decided if I wasted my money on the couplers yet....they kinda look like big black dildos to me, might pull them out and use the portion I cut off to use some copper 45* elbows instead like this one:


-or I could just trim th elbos down shorter so the filter is right after the 45* turn.....

So I have the chain mocked into place and set the lunchbox into the frame, and ziptied the bike pedal I wanna use for the kickstarter in place to get an idea for the feel of things




Now that I'm at where I am..... I've come to a bit of a crossroads with the scheme of the build.....I almost like the beaten up vintage appearance of the lunchbox as-is....which makes me feel like I might want leave it the way it is instead of painting it....but then I feel like if it's the only part of the bike that doesn't look "new" then it might upset the overall appearance....

so, I have to decide between :

1) Leave lunchbox the way it is and mount it, leave the tank in it's current banged up state(missing emblems and all), and do some creative "distressed" paintwork on the rear fender to match the tank

2) Smooth out the tank, shave the emblem recesses, and go with fancy new paint. Paint fender and lunchbox to match.

Either way I want to probably black-out the engine and introduce more elements of copper, regardless of paint-scheme.....

Thats a really nice build you've got owing on there! I'm doing a similar build. I think you're right about the intakes, they remind me of donkeys Knobs! Like the copper idea too!
Like the tattoos!
I like the re-use of the stock tank; I think it's better-looking than people usually give it credit for, and the capacity is great. Having said that, with better ignition and thorough carb tuning, 50+mpg isn't unreasonable, and a 2-gal tank becomes workable.

As for the intakes... maybe this would just complicate tuning, but as I look at it, how about turning the two intake inwards instead of downwards, and using a single (larger) filter tucked below the seat?
how about turning the two intake inwards instead of downwards, and using a single (larger) filter tucked below the seat?

I did think about that, but I'd have to find a "y" fitting that has two legs at 45* angles and 2" dia with the third leg being more like 3" to put a filter on.....I don't think I'll be able to find that, and what it would cost me to make one and the effort involved would probably be much more than just swapping out the elbows for copper.

or, I could just shorten the black elbows......PS'd really quick to get an idea....

got a little bit done tonight....bent up some flat stock to make mounts for the lunchbox and started working on modifying the stock handlebar mounts for more rise (until I ran into a roadblock....didnt have the right drill bit to finish)



It's mounted this way so that the "door" can open without hitting anything so I'll have access to the fuses in the event of one blowing out.

Step one of making risers: Cut stem off original bar mounts


Step 2: drill hole the same size as previous stem through center (started small and worked my way up)


I ended up not having a bit large enough, so I'll have to pick up the correct bit and re-visit this.
God a pretty solid amount of work done tonight....

Luke's (Pirite) dad (known as "The Don") came through with a 1/2" drill bit I needed to get the risers for the handlebars finished....

I posted steps one and two previously....cutting the existing "stem" off the bar clamps and start step-drilling up to 1/2"

drilling 1/2" today:


step 3: press a 4" piece of 1/2" bar stock into the hole drilled in the clamp, with about 3/16" left before being flush on the other side


step 4: weld the bar stock to the clamp (PISS, this pic came out blurry, sorry)


step 5: file the weld down so the clamp is functional again (GODDAMN auto flash sux!)


step 6: make a 1.25" sleeve out of some 3/4" tubing, then smash the top washer from the original mounts down to pinch the tubing against the clamp


step 7: Weld all that stuffs together


step 8: Tap the end for a nut


step 9: test mount


step 10: Paint and install (forgot to take pics close-up of the finished mounts)



In that last pic, you can see I ended up not liking the look or feel of the drag bars, so I put these cruiser style bars on that were kicking around. (also, there's a lot of damn bikes in here)

Next, I decided that instead of trying to cram the battery and the starter solenoid into the lunchbox, it would be nice to have half of it available for storage for things like my phone and wallet and house keys while I ride, maybe a baseball hat too...So I decided to whip up a box to hang beneath the lunchbox to house the mini-battery I picked up and the starter solenoid (this will also make it super easy to charge the battery or connect for a jump should I ever run into a situation where I have a dead battery)

So I took some measurements and laid out a box template on some 1/16" steel plate and cut it out, and cut some grooves to make bending it nice and easy



finished pattern:


Then I bent it to shape and welded the corners:



Then I welded some bolts to the battery box


then I drilled holes through the little cage I made to hold the lunchbox, and also holes through the lunchbox



the bolts sandwich the battery box and the lunchbox around the cage and holds everything nicely in place. I used some rubber isolators to keep vibration down




(oh yeah, I also trimmed down the silicone elbows so they don't look like dongs anymore)

Battery and solenoid trying out their new home:


Then I made some hooks and a divider so the stock battery rubber strap mount could be re-used and separate the battery from the solenoid, and made up some wires


I wrapped the battery in some rubber sheeting I had so it wont be able to bounce around, and has a nice snug fit into the box

The completed box back in it's home:


Then I had luke take apart the bike pedal for the kickstarter and paint the inner piece black



Then I sat on it


Then we noticed that if I put my legs down on the ground, as if at a stop light, the kickstarter was kinda digging into my thigh, so we took it off and heated it up with a torch and massaged it to be tucked in more


Then we decided we should probably see how the old exhaust fits.....it was pretty close as-is, but was swept up a little high and wouldn't allow the lunchbox to be open. I also wanted it to be parallel with the bottom frame tube.....so I mounted it up and bent it to where I wanted it and welded a mounting tab. I forgot to take pictures during this, but here's the results


Then I sat on it again, and made some vroom vroom noises.

well, I spent about 5hrs out in the garage tonight......couple things went well, couple things went bad. For starters, my new drillpress fucking rules (never had one before, I love having one)

I'll start with what went well....

Decided to jump into modifying the kickstart lever to accept the bike pedal I bought for it.

Cut the existing stem off the lever:


enjoy use of new drill press to bore a hole progressively up to 1/2" through the end of the lever where the stem used to be:


Tap to M14x1.25 (Ended up grabbing the tap from Grainger for $10 so now I own it, instead of borrowing one)


Thread in pedal:



Test fit:







As you can see, the pedal matches the seat springs nicely. pretty stoked about the kicker....

Now, the shit that pissed me off.....

Went to start making up some forward control pegs....spent about 3hrs cutting steel and drilling a ton of holes and welding....and then realized I forgot to account for the engine cases sticking out....and then tried a quick fix to space the brake side out past the case, and hate the way it looks. Will have to go back to the drawing board on these....




I'm almost considering mid controls using the original muffler mount points on the bottom frame tubes just cause it will be way easier, but I really think forwards will be more comfortable for riding..... Le Sigh
Been a while since I worked on the bike or updated this.....

spent a few hours on it tonight, didn't take any "in process" pics cause I just kinda got in a groove and rolled with it.....but I've finished the shifter side forward control setup.

I started out by making the foot peg and mount, then a brace to the engine case. Then I made a collar to insert the bronze bushing into, and welded a tab to it for the linkage arm to connect to. Then I bent up a piece of round bar and tapped the ends for the mini heim joints. Then I cut the stock shift lever down and drilled a hole in it and connected the linkage. Then I used a shitty old box-end wrench and a piece of a cheap hoodpin I had laying around to make the shift arm. humorously, the rubber from the stock shift arm fit nicely on the hoodpin. All that's left is to finish the electrical and make the brake-side forward control....then it's ready for clean-up and paint.







the basics are done, I'm going to do a few things to clean it up and fancy it up later on.
Wondering about your kickstart pedal? I like the idea of having it threaded so it can be changed out but is there enough meat left to withstand the abuse of kicking it?
Wondering about your kickstart pedal? I like the idea of having it threaded so it can be changed out but is there enough meat left to withstand the abuse of kicking it?

absolutely. that's over a half inch deep, with about 1/8" all around the hole where I tapped it. there's more meat there than the crank on a bicycle where the pedal threads in and on a bicycle you can stand and pedal at the same time without issue.....


I've got the other pedal from that set and obviously all the proper bits and thread tap.....if someone wants to send me their kickstart lever I'd be happy to modify it for the pedal and send it back with the pedal for $20+return shipping....
Finally got around to making the brake side forward control tonight after a much needed clean-up of the garage (thanks to my buddies Checko and Luke for helping out).

Grabbed a dirtbike master with reservoir on ebay for $13 shipped and Luke brought a busted MAC wrench from work, and this is what happened with it:






I've been tinkering a little bit here and there for an hour or two at a time and have a few things coming together.....

I extended some wires and shortened a few others to make the routing of the harness work better for where I've located everything. I also made a panel in the lunchbox to hold the electrical componants out of the weather and started working on a chain tensioner.